1. Field of the Invention
This invention relates to two-degree-of-freedom gyroscopes and more particularly pertains to a two-degree-of-freedom gyroscope in which the rotor is elastically suspended from a wire held taut within a drive shaft for the rotor and wherein the rotor is radially supported by magnetic repulsion.
2. Description of the Prior Art
Most of the two-degree-of-freedom displacement gyroscopes which are presently in use are of two types: the free-rotor type of gyroscope and the dry-tuned type of gyroscope. In the free-rotor type of gyroscope, the rotor is supported on a spherical electrostatic bearing or on a spherical autolubricated gas bearing. In the dry-tuned type of gyroscope, the rotor is supported on a mechanical spring of flexure system which must be precisely tuned to resonate at the spin frequency. Both of these types of displacement gyroscopes are fabricated from costly precision-machined parts. In addition, it is critical to their proper operation that a very high degree of skill and care be exercised in their assembly and in their adjustment for balance. The result is that the cost of these presently available displacement gyroscopes is a major portion of the cost of an entire inertial navigation system.
There is a need, therefore, to provide a less costly two-degree-of-freedom displacement gyroscope which requires less precision, skill and care in its fabrication, assembly and adjustment. It is an object of the invention described herein to meet these requirements.
Most of the rate gyroscopes which are presently in use are of the single-degree-of-freedom type. The rotor is mounted on a gimbal which, in the higher precision versions, is a sealed float immersed in a fluid contained within an outer housing. These gyroscopes have a relatively large number of component parts and are therefore expensive to make. An additional consideration, inertial navigation systems which employ single-degree-of-freedom rate gyroscopes require the use of more of them than would ordinarily be necessary were a satisfactory two-degree-of-freedom rate gyroscope available. These navigational systems are therefore larger, more complex and more costly to produce than they would be if they used two-degree-of-freedom rate gyroscopes.
Therefore, there is also a need for a two-degree-of-freedom rate gyroscope which is made up of comparatively fewer parts. It is another object of this invention to meet this requirement.